Adjusting mechanism for band-knife leather splitting machine



Oct. 30, 1962 J. M. WEBER 3,060,714

ADJUSTING MECHANISM FOR BAND-KNIFE LEATHER SPLITTING MACHINE Filed 001;. 22, 1958 //Vl//V/'0/? .7555; MIOWIEL M520? 2/ ,da d w Unite States The present invention relates to a band-knife adjusting mechanism for a band-knife leather splitting machine.

During the operation of machines of this type, as shown and described, for example, in the US. Patent No. 1,670,514, the band knife is normally in constant engagement with a grinding mechanism, the grinding wheels of which not only keep the cutting edge of the knife sharp at all times, but also grind the edge at the particular angle as required by the type of leather to be split. Since the cutting edge of the band knife is thus subjected to a constant abrasion, the distance between this edge and a vertical plane extending through the axes of rotation of the leather feed rollers of the machine also changes during the splitting operation. Consequently, if the splitting operation is to be accurate, this distance must be frequently corrected. For this purpose, the manufacturers of such splitting machines previously provided an adjustable mark at a point above the band knife and adjusted this mark so as to be at a certain distance from the mentioned plane passing through the axes of the feed rollers. After being once adjusted to such a distance by the manufacturer of the machine, the position of this mark was supposed to remain unchanged. If the leather to be split was of a different kind than in a previous splitting operation, the person in charge of the machine had to readjust the guides of the band knife so that the latter would be in a position in accordance with such kind of leather. The guides of the band knife were therefore adjusted so that the cutting edge of the knife would extend either in front of, within, or behind the plane passing through the mark. As long as atent these adjustments were carried out by a person who was really qualified to do so, this method was successful in that any kind of leather could be properly split. If, however, the splitting machine was operated by an insufiiciently skilled person, such person did not always properly check that the cutting edge of the knife was at the proper distance from the plane passing through the axes of the feed rollers in accordance with the kind of leather to be split. Such improper adjustment then resulted in oifcuts and in a waste in material.

It is an object of the present invention to provide a band-knife adjusting mechanism for band-knife leather splitting machines which increases the accuracy of the splitting operation, avoids offcuts and Waste, reduces the wear upon the band knife, and may be reliably operated even by an unskilled or semiskilled person to adjust the knife to the proper position for each particular kind of leather.

Similarly as in previous machines of this type in which the band knife is constantly kept in a sharp condition by the rotary grinding wheels of a grinding mechanism,

the present invention also provides a mechanism for adjusting the position of the band knife in relation to the kind of leather to be split so that the cutting edge of the knife will be at a certain distance from the vertical plane passing through the axes of the leather feed rollers of the machine. This mechanism also includes a mark for gauging the distance between the cutting edge and the mentioned vertical plane, and means for adjusting such mark relative to such plane.

Proceeding from a leather splitting machine which is to FIGURE 1, as seen in the direction "ice provided with the means as above described and with an adjustable mark at a position above the plane of the cutting edge of the band knife, the present invention further provides a second mark at a point underneath the plane of the cutting edge of the band knife and in such a position that both marks will lie within the same vertical plane and be adjustable in unison with each other by the same adjusting means. By proceeding according to the invention, the operator of the splitting machine merely needs to watch that the cutting edge of the band knife will just touch the vertical plane passing through the two marks. If a kind of leather is to be split which is different from the previous kind it will merely be necessary to adjust both marks with respect to the vertical plane passing through the axes of the feed rollers and then to adjust the guides of the band knife so that the cutting edge thereof will just touch the plane passing through the two marks. The operator of the machine therefore only needs to check once in a while whether the two marks and the cutting edge of the knife still lie within the same vertical plane. The invention further provides suitable means in the form of a spindle or a similar device for adjusting the two marks, which are held in a fixed position relative to each other by a connecting means, so that these marks or the vertical plane passing therethrough will be at the desired or required distance from the vertical plane of the axes of the feed rollers, in which position the marks may then also be locked.

Another preferred feature of the invention consists in providing at least one of the two marks in the form of a slit, in providing a light source behind such slit, and in associating the other mark with a selenium cell in such a manner that the beam of light passing through the first slit can impinge upon theselenium cell only if the cutting edge of the band knife does not touch the vertical plane passing through the two marks or slits. The invention further provides suitable control means for automatically adjusting the band knife to a position in which its cutting edge will just touch the vertical plane which is determined by the two marks or slits. The band knife Will thus always be automatically adjusted in accordance with the position of the marks or slits, and it no longer requires frequent inspections to determine whether it is in the proper position. The grinding mechanism which is associated with the band knife to keep it sharp at all times may then be adjusted to the respective position of the knife so that the cutting edge of the latter will always be ground to the proper lip angle in accordance with the setting of the marks or slits. The only function which the operator still has to carry out therefore consists in adjusting the distance between the axes of rotation of the two grinding wheels and, if it should become necessary by a different kind of leather to be split, in adjusting the distance between the marks and thus between the cutting edge of the knife and the vertical plane passing through the axes of the feed rollers. As long as this distance remains constant, the grinding wheels, after having once been adjusted relative to the band knife, may be moved together with the band knife by the-provisionof a positive connection between them and the adjustable gaging means for the band knife.

Further objects, features, and advantages of the present invention will appear from the following detailed description thereof, particularly when read with reference to the accompanying diagrammatical drawings of a preferred embodiment of the automatic adjusting mechanism according to the invention, in which-- FIGURE 1 shows an elevational view of the control means for adjusting the position of the band knife;

FIGURE 2 shows a left side view taken at right angles shown by the arrow A; while v 3 FIGURE 3 shows a plan view of FIGURE 2. Referring to the drawings, a shaft 1 which is rotatably mounted carries a pair of Worms 2 spaced at a certain distance from each other, only one of which is shown. Eachiworm 2 is in engagement with a curved rack of gear teeth provided at one arm of a bell crank 3 (FIG- URE 3) which, when pivoted about a pin 3' in a clockwise direction as viewed in FIGURE 3, acts with its other arm upon one of the guides 18 of the band knife 4 to adjust the same in a direction opposite to that indicated in FIGURE 1 by the arrow A. For rotating shaft 1 and for thus adjusting the position of bandknife 4, an electric motor 5 may be provided which is connected through a worm-reduction gearing 6, 7 with one clutch half of a. magnetic clutch 8 which is adapted to be engaged with, or disengaged from, the other clutch half thereof mounted on shaft 1 in a manner to be de scribed more fully hereinafter.

' The cutting edge 4' of band knife 4 is adapted to cooperate with a pair of marks which in the particular embodiment illustrated consist of two slits 9 and 10 disposed within 'a common vertical plane and preferably provided within the two arms of a U-shaped member 11 which is adapted to be shifted back and forth within a horizontal plane as viewed in FIGURE 1. For this purpose, member 11 is mounted on a spindle 13 which is adjustable within and supported by a stationary nut-like hearing member 12 mounted on the machine frame. The

free end of spindle 13 carries a dial 14, the graduations 15 (FIGURE 2) of which are marked so that the vertical plane passing through slits 9 and 10 will be spaced at a distance of 3 mm. from the vertical plane passing through the axes of rotation of the leather feed rollers 19 and 20 of the machine when a stationary mark, for

example, a dial pointer 21 (FIGURE 1), coincides with the most central of the graduation lines 15 on dial I4; Since the vertical plane passing through slits 9 and '10 in the U-shaped member 11 forms the plane of adjustment for the cutting edge 4 of band knife 4, it is possibleproperly to split any kind of leather by turning shaft l'so as to adjust the band knife in such a manner that its cutting edge 4' will just touch the vertical plane passing through slits 9 and 10. If the kind of leather changes and if, for example, a thinner leather is to be split, it will be necessary to reduce the distance between the cutting edge 4 and the vertical plane passing through the axes of the feed rollers 19 and 20. Dial 14' must then be turned, for example, to such an extent that the plane passing through slits 9 and 10 will be spaced at a distance of 2.5 mm. from the vertical plane passing through the axes of feed rollers 19 and 20, whereupon the cutting edge 4' of the band knife should be adjusted to the plane passing through slits 9 and 10. The grinding wheels 22 and 23 of the grinding mechanism which during operation are constantly in engagement with the cutting edge 4' of the knife to keep it sharp at all times are then adjusted so that the lip. angle of the cutting edge will be smaller than the lip angle which was previously required'when the distance between the plane of slits 9 and 10 and the vertical plane of the axes of feed rollers 19 and 20 amounted to 3 mm.

If the leather to be split is relatively thick, the distance between the cutting edge 4' of the band knife and the plane passing through the axes of feed rollers 19 and 20 must be increased, for example, to 3.3 mm. Dial 14 should therefore be turned in the opposite direction. In this case, the grinding wheels 22 and 23 are to be ad justed relative to the cutting edge 4' so that the lip angle thereof will be greater than the lip angle which would be required when the mentioned distance amounts to 3 mm. While splitting different pieces of leather of the same kind, the operator of the machine therefore only needs to watch that the cutting edge 4' will always coincide with the plane passing through slits 9 and 10. Since the position of grinding wheels 22 and 23 remains unchanged as long as the position of the plane passing through slits 9 and 10 is not changed, they may also be mounted so as to be adjustable together with the ad- 7 justable gaging means of band knife 4. For this purpose,

a positive connection of some kind may be provided, for example, between one or both arms 11 of the adjustable gaging means 11, 12, 13,114 and the grinding mechanism 22, 23 as indicated by the dash line 30 in FIGURE 2.

If the mechanism is to be designed so that the cutting edge 4' of the band knife will at all times be automatically adjusted to touch the plane passing through slits 9 and 10, a suitable control mechanism may be provided in association with slits 9 and 10. Thus, for example, slit 10 may be associated 'with a light source 16 and slit 9 with a selenium cell 17. If a beam of light then passes through both slits 10 and 9 and impinges on the selenium cell 17, motor 5 will be rendered effective to turn shaft 1 so as to shift band knife 4 in a direction opposite to that of arrow A in FIGURE 1 until the cutting edge 4 of the band knife will intercept the beam and thereby immediately stop the movement of shaft 1. Any suitable means may be used to render the motor 5 operative as light impinges on the selenium cell 17, though it is preferred to provide a continuously operating motor 5 and electromagnetically engage the electromagnetic clutch 8 as light impinges on the selenium cell 17. Any suitable circuit including conventional amplihers and the like may be used to achieve this result. However, since such circuits are well known in the prior art, they are not specifically shown herein. Since in the known types of splitting machines the band knife 4 is guided so as always to be in a sliding engagement with the guides 18, a proper automatic adjustment of the knife relative to the leather to be split may be relied upon at all times. Thus, when the cutting edge 4 becomes worn and its width is reduced by grinding wheels 22 and 23, it will only be necessary to adjust the knife by moving the same in one direction, whereby the cutting edge 4 is brought back to its proper position relative to the vertical plane extending through the axes of feed rollers 19 and 20 as well as relative to the grinding wheels 22 and 23.

Before the machine is to be stopped, it is very advisable to reverse the movement of the band knife in order to avoid jags in the cutting edge thereof, particularly if the machine is electrically controlled so that the cutting edge of the band knife always coincides with the mentioned plane. When the main switch of the machine is then operated, the same preferably first reverses the movement of the control motor 5 so that the latter will move the band knife out of engagement with grinding wheels 22 and 23 until its rear edge will engage a limit switch serving as a circuit breaker and thereby stop the further operation of the machine. .When the machine is to be started and is switched on, the circuit is so arranged that at first the grinding disks and the band knife will be started without, however, being in engagemen-t with each other. Thereafter, the band knife will be moved to the respective preselected position to start the splitting operation, and at the same time or thereafter the grinding disks will also be brought into engagement with the band knife.

The particular mechanical connecting means between the individual parts of the adjusting mechanism, according to the invention, as well as the particular electrical circuit and control means for the automatic operation of the mechanism have not been shown or described in detail as they may be of various types generally known in the art.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim is:

1. In a leather splitting machine having an endless band knife adapted to move continuously in one direction, a. grinding mechanism including grinding wheels for maintaining the cutting edge of said band knife constantly in a sharp condition, and feed rollers for feeding the leather during the splitting operation, the improvement comprising a mechanism for adjusting said band knife so that the cutting edge thereof will be disposed at a certain distance from the vertical plane passing through the axes of rotation of said feed rollers, said mechanism comprising a member having a pair of marks thereon spaced in a vertical direction from each other and disposed above and below said band knife within a second vertical plane, means for adjusting said member and said marks thereon relative to said first-mentioned vertical plane passing through the axes of said feed rollers, and means for adjusting said band knife so that its cutting edge will touch said second vertical plane passing through said two marks.

2. A mechanism as defined in claim 1, wherein at least one of said marks forms a slit in said member, and further comprising a light source disposed behind said slit, said second mark comprising a selenium cell, the beam of light passing from said light source through said slit being adapted to hit upon said selenium cell only as long as said cutting edge of said band knife does not touch said vertical plane passing through said marks, and means controlled by said selenium cell for adjusting said band knife so that its cutting edge will always tend to touch said vertical plane passing through said marks.

*3. A mechanism as defined in claim 1, wherein said member supporting said marks is U-shaped, having one arm disposed above said band knife and the other below said band knife, said marks forming a slit in each of said arms, said slits being disposed within the same vertical plane, a light source disposed behind one of said slits and a selenium cell disposed behind the other slit, the beam of light passing from said light source through said slits being adapted to hit upon said selenium cell only as long as said cutting edge of said band knife does not touch the vertical plane passing through said slits, said means for adjusting said U-shaped member and said slits, said light source, and said selenium cell thereon relative to said vertical plane passing through the axes of said feed rollers comprising a screw spindle, graduated dial means on said spindle to permit an accurate adjustment of said vertical plane passing through said slots relative to the vertical plane passing through the feed roller axes, and means controlled by said selenium cell for adjusting said band knife so that its cutting edge will always tend to touch said vertical plane passing through said slots.

4. A mechanism as defined in claim 1, further comprising means for connecting said grinding mechanism to said band-knife adjusting mechanism so that an adjust merit of the latter Wiil also result in an adjustment of said grinding mechanism.

5. In a leather-splitting machine having roller-type feed means with the axes of rotation thereof disposed in a first plane and knife means for splitting the leather provided with a knife edge adapted to be adjusted with respect to said first-mentioned plane, the combination comprising adjustable gaging means for preselecting the position of said knife edge, actuating means for changing the position of the edge of said knife means with respect to said plane, and means operatively connecting said adjustable gaging means with said actuating means for automatically controlling said actuating means in dependence on the position of said adjustable gaging means and the position of said knife edge with respect thereto to thereby maintain the knife edge of said knife means in the preselected position thereof with respect to said adjustable gaging means and therewith with respect to said plane.

6. In a leather-splitting machine having roller-type feed means with the axes of rotation thereof disposed in a first plane and knife means for splitting the leather provided with a knife edge adapted to be adjusted with respect to said first-mentioned plane, the combination comprising adjustable gaging means for preselecting the position of said knife edge, selectively operable actuating means for varying the position of the edge of said knife means with respect to said plane, said adjustable gaging means being manually adjustable, means operatively connecting said adjustable gaging means with said actuating means for automatically controlling said actuating means in dependence on the position of said knife edge with respect to said adjustable gaging means so as to maintain the knife edge of said knife means in predetermined position with respect to said adjustable gaging means and therewith with respect to said plane, and grinding means for sharpening said knife edge operatively connected with said adjustable gaging means.

7. In a leather-splitting machine having roller type feed means with the axes of rotation thereof disposed in a first plane and knife means for splitting the leather having a knife edge adapted to be adjusted in the spacing thereof with respect to said first-mentioned plane, the combination comprising first means forming adjusting mark means for preselecting the position of said knife edge, normally inoperative second means operative upon activation thereof for changing the position of said edge of said knife means, and means for rendering said second means effective to change the position of said knife edge in dependence on the position thereof with respect to said mark means to thereby maintain said knife edge in a predetermined position With respect to said first-mentioned plane.

8. In a leather-splitting machine, the combination according to claim 7, further comprising a grinding mechanism for sharpening said knife edge including means operatively connected with one of said first means for simultaneously readjusting the grinding mechanism with an adjustment of said mark means.

No references cited 

